It theoretically can be used for this yes. At the moment it's not used for that. It's been experimented on the 3 but not much has come of it.

This isn't correct. Each bus updates its location every 2 minutes (plus or minus some amount to create randomness and help with load.) Regardless it is real time information.

Thats what I meant. Its not real time in the sense that you can see EXACTLY where the bus is. It would create too much congestion on the data network to have updates every 30 seconds or something like that.